<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    body {
      margin: 0;
    }
    .header {
      display: flex;
      align-items: center;
      height: 24px;
      -webkit-app-region: drag;
      user-select: none;
    }
    .header-basic {
      width: 14px;
      height: 14px;
      line-height: 14px;
      margin-left: 5px;
      font-size: 12px;
      color: #333;
      text-align: center;
      border-radius: 50%;
      -webkit-app-region: no-drag;
    }
    .header-close {
      background-color: rgb(255, 72, 0);
    }
    .header-minimize {
      background-color: rgb(255, 179, 0);
    }
    .header-maximize {
      background-color: rgb(47, 255, 0);
    }
  </style>
</head>
<body>
  <div class="header">
    <div class="header-basic header-close" onclick="preloadApis.handleClose()">x</div>
    <div class="header-basic header-minimize" onclick="preloadApis.handleMinimize()">-</div>
    <div class="header-basic header-maximize" onclick="preloadApis.handleMaximize()">+</div>
  </div>
</body>
</html>